This application claims the priority of Korean Patent Application No. 2002-62075 filed on Oct. 11, 2002 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a wireless communication medium which can sense and generate a radio frequency (RF) signal necessary for communicating with a card reader or a contactless communication system, processes an analog signal to generate power necessary for driving a radio frequency identification (RFID) system, and processes a digital signal between an analog signal processor and a central processing unit (CPU) based on a communication protocol specified in ISO 14443, and a method for operating the same.
2. Description of the Related Art
In a method of processing an analog signal of a conventional RFID system, a RF hardware signal processor is broken down by a high voltage from an antenna, and thus the conventional RFID system loses its functions. Thus, the conventional RFID system cannot be used as a contactless RFID system. Also, a circuit is complicated and a large device value is required in order to prevent the contactless RFID from losing its functions.
In the conventional RFID, only a circuit, which processes an analog signal, is constituted and connected to a CPU. In other words, the CPU carries out functions of a digital signal processor without the digital signal processor or a digital signal processor carries out limited functions. Thus, it takes much time for the CPU to process such a digital signal and the whole performance of the conventional RFID deteriorates.
In addition, the conventional RFID uses a circuit which modulates a signal being transmitted to generate a BPSK-modulated signal by applying a carrier frequency of 874 KHz to a flip-flop circuit. Here, glitch necessarily occurs in the BPSK-modulated signal.